Ear plug

ABSTRACT

A sound attentuating ear plug molded of a single piece of material intended to fit into the ear canal and be held there without external means. The plug is made of a material having special sound attentuating qualities and is provided with a vent that permits the equalization of pressure within the ear canal and the surrounding atmosphere.

[111 3,872,559 1 Mar. 25, 1975 1 EAR PLUG [76] Inventor: Charles Leight, 5356 W. Pico Blvd,

Los Angeles, Calif 90019 [22] Filed: Jan. 11, 1973 [21] Appl. No.2 322,749

[52] U.S. Cl. 128/152 [51] Int. Cl. A611 11/02 [58] Field of Search 128/151, 152; 181/23, 25

[56] References Cited UNITED STATES PATENTS 2,672,863 3/1954 Leight 128/152 3,259,128 7/1966 Leight 3.736929 6/1973 Mills 128/152 FOREIGN PATENTS OR APPLICATIONS 578,613 7/1946 United Kingdom 128/151 Primary Examiner-Richard A. Gaudet Assistant Examiner-G. E. Dunne Attorney, Agent, or Firm-Fulwider, Patton, Rieber, Lee & Utecht [57] ABSTRACT A sound attentuating ear plug molded of a single piece of material intended to fit into the ear canal and be held there without external means, The plug is made of a material having special sound attent uating qualities and is provided with a vent that permits the equalization of pressure within the ear canal and the surrounding atmosphere.

6 Claims, 4 Drawing Figures 1 EA'R PLUG BACKGROUND OF THE INVENTION This invention is an improvement on the ear plug shown in my prior US. Pat. No. 2,672,863, issued Mar. 23, 1954. While that ear plug was a considerable improvement over plugs then previously existing, it had the disadvantage that two separate pieces were required and the plug had to be positioned in a special way so that its insertion into and removal from the ear canal could be best accomplished.

In the present invention, the ear plug is molded as a one-piece member, while retaining the advantages of the two-piece construction previously shown, and the shape of the plug has been improved so that special positioning is no longer required.

SUMMARY OF THE INVENTION DESCRIPTION OF THE DRAWING FIG. 1 is a side elevational view of the improved ear plug indicating how it is installed in the ear and ear canal;

FIG. 2 is a front perspective'view of the ear plug;

FIG. 3 is an enlarged view, mainly in cross-section, showing the ear plug as it comes from the mold; and

FIG. 4 is a fragmentary view of the front tip of the ear plug, partially in section, showing the form of the ear plug after it has been trimmed.

DESCRIPTION OF PREFERRED FORM As best seen in FIGS. 1 and 2, the improved ear plug of the present invention consists of a generally cylindrical member 10 having a body portion 12, and end portion 14 at one end of the body, and a hollow flared section 16 at the other end of the body 12. The body 12 is a cylindrical section and the end 14, having a somewhat conical shape, is concentric with the body, as is the flared section 16. The whole device may thus be considered as a solid of revolution, and the recess 18 in the flared portion 16 is also concentric with the axis of the body. It will be noted that the body 12 is somewhat larger in diameter than the end 14, and the two are joined by a sloping shoulder 20.

It will be appreciated that the ear plug may be made .in different sizes, but to indicate the relative dimenthe same distance measured along the axis of the ear plug 10. The maximum diameter of the flared portion 16 may be 0.525 in., and the distance from the junction of the flared portion 16 and the body 12 to the end of the flared portion may be 0.330 in. The body may have a length of 0.200 in., and the end have a length of 0.400 in. As mentioned, these dimensions are byway of example only and to indicate the proportions of the improved ear plug.

The opening 18 within the hollow flared end 16 forms walls that, in the example given, may have a thickness of 0.065 in., a thickness which has sufficient mechanical strength to permit the ready insertion and removal of the ear plug in the ear, while still not making the plug heavy or clumsy to use.

As indicated in FIG. 3, when the plug 10 is molded, a tip or projection 22 is molded on the apex of the end 14 and a similar tip 24 is molded in the opening 18 of the flared portion 16, both the tips 22 and 24 being preferably located on the axis of the plug 10. It will also be noted in FIG. 3 that'the main portion of'the plug 20' is of a foam construction, but that a skin portion is formed on the surface adjacent the mold. While the foam portion consists of a material having an open cell form, the skin, in effect, forms a closed surface over the open cells. The tips 22 and 24 have the skin formed on their surfaces, and the tips are of a sufficient diameter, such as 0.035 in., that the central portion of the tips is the open cell configuration of the main portion of the ear plug 10.

After the plug 10 is removed from the mold, the tips 22 and 24 are cut off, as indicated in FIGS. 3 and 4, at the point of connection to the plug 10. As a result, the skin is broken at the axis of the plug, both on the apex of the point 14 and in the opening 18. Consequently, with the open-cell construction of the ear plug, air may slowly escape from the ear canal to the surrounding atmosphere until the pressures are equalized. If the atmospheric pressure increases, the pressure within the ear canal may again be equalized to eliminate dizziness, vertigo, or other discomfort. It will be realized that the rate of flow of air through the open cellfoam will be relatively slow and hence, the pressure equalization will not in any way affect the sound attenuating properties of the ear plug 10.

While various products may be used for the material of which the ear plug 10 is made, it has been found that one of the most satisfactory materials to make the plug 10 is a foamed neoprene to which a small amount of cellulose floc has been added for maximum attenuation of the sound both by absorption and by blocking of the canal. The material also has the characteristic of forming a thin skin next to the surface of the mold. By way of example, a formula along the following lines has been found to be very satisfactory.

FORMULA Material Function 50 Neoprene Type W- Basic Polymer q.s. Coloring less than I Z0 9 (Wax-Like Solid Wax Plasticizer Plasticizer Wyexley & Co., New Jersey) 1 Magnesium Oxide Acid Inhibiter less than 9 Unicel S (50% Blowing Agent Sodium Bicarbonate, 50% mineral oil) less than 9 Process Oil (Light Softener weight mineral oil) about 4 Stearic Acid Activator for Blowing Agent 3 Zinc Oxide Cure Activator less than 6 Lithopone Toner and Filler less than 6 Whiting Filler less than 1 Naugawhite Powder Anti-oxidant (Alkylated Bis Phenol) F ORMULA-Continued Material Function lessThTahT NAZI'Q-M efc'a'pto Accelerator for Cure lmidayolin) 4 Dioctyl Sebecate Plasticizer 5% Sodium Bicarbonate Blowing Agent 1 Titanium Dioxide Toner l Cellulose Floc Sound Attenuator It is to be understood that this particular formula is not the only one that will produce satisfactory results, since it is the mechanical qualities of the ear plug that are important, rather than the chemical properties. The principal requirements are that the plug be'made of a soft, open-cell, sponge material with a skin formed on its outer surface and with the skin broken to permit the venting of the ear canal.

In using the device, the tip. of the ear plug is inserted into the ear canal by inserting the index finger into the cavity 18 and pressing the plug into the ear until the shoulder 20 bears against the portion of the ear surrounding the end of the canal. At this point, the end portion 14 fits into the canal to plug the latter and to reduce the transmission of noise along the canal. The end 14 also acts to hold the plug 10 in the ear. The shoulder 20, by bearing against the portion of the ear surrounding the entrance to the canal, reduces the amount of sound that is transmitted along the canal and also reduces the sound transmitted by the flesh and bone structure to the inner ear. The weight of the ear plug 10 is very light, and it can thus be worn for long periods of time with a minimum of discomfort. The venting of the canal through the open cell foam prevents changes in atmospheric pressure from causing diziness, vertigo, or other discomfort.

To remove the ear plug 10, it is-only necessary to grasp the wall of the flared section 16 between the thumb and index finger and pull outwardly to remove the tip 14 from the canal. It will be recognized that the flared wall 16 that extends completely around the axis of the ear plug 10 represents an improvement over the form of construction shown in US. Pat. No. 2,672,863, where a tab was provided that had to be located in a particular position in the ear so as not to interfere with the structure of the ear, while still permitting the tab to be grasped for removal of the ear plug.

From the foregoing, it will be seen that there has been provided an ear plug fully capable of achieving the objects and securing the advantages heretofore set forth. While a preferred construction has been disclosed, it is to be understood that the patent is not to be limited to the particular form or arrangement of parts herein described and shown, except as limited by the following claims.

I claim:

1. A unitary, resilient ear plug which includes:

a cylindrical body portion;

a generally conical end portion connected to a first end of said body portion coaxially therewith and forming an extension thereof;

a hollow flared portion comprising a wall connected to a second end of said body portion and forming an extension thereof, said flared portion opening in a direction away from said body portion and defining a recess coaxial with said body portion and adapted to receive the tip of a finger whereby said body and end portions of said plug may be urged into position in an ear canal, said flared portion being so sized and positioned that a single thickness thereof may be grasped for removal of said plug from an ear canal;

said body, end, and flared portions comprising a single, unitary structure formed of a self-skinning, resilient, open cell, sponge material having a skin covering the surface thereof; and

a first vent opening in said skin covering on said conical end portion and a second vent opening in said skin covering on said second end of said body portion, said first and second vent openings permitting venting of an ear canal through said open cell foam material when said plug is positioned in the canal.

2. The ear plug of claim 1, wherein the wall of said hollow flared portion extends outwardly from said body portion, whereby the diameter of said flared portion is at least equal to the diameter of said body portion.

3. An ear plug as defined in claim 1 in which said skin covers all of said structure except for two small areas on opposite ends of said plug to provide for pressure equalization when said plug is in use.

4. An ear plug as defined in claim 1 in which said conical end has a maximum diameter less than that of said cylindrical body, said end and said body being joined by an angularly positioned shoulder.

5. An ear plug as defined in claim 4 in which said skin covers all of said structure except for two small areas on opposite ends of said plug to provide for pressure equalization when said plug is in use.

6. An ear plug as defined in claim 4 in which said conical end is of a size to fit within the ear canal and said shoulder is of a size to bear against the portion of the ear surronding said canal. 

1. A unitary, resilient ear plug which includes: a cylindrical body portion; a generally conical end portion connected to a first end of said body portion coaxially therewith and forming an extension thereof; a hollow flared portion comprising a wall connected to a second end of said body portion and forming an extension thereof, said flared portion opening in a direction away from said body portion and defining a recess coaxial with said body portion and adapted to receive the tip of a finger whereby said body and end portions of said plug may be urged into position in an ear canal, said flared portion being so sized and positioned that a single thickness thereof may be grasped for removal of said plug from an ear canal; said body, end, and flared portions comprising a single, unitary structure formed of a self-skinning, resilient, open cell, sponge material having a skin covering the surface thereof; and a first vent opening in said skin covering on said conical end portion and a second vent opening in said skin covering on said second end of said body portion, said first and second vent openings permitting venting of an ear canal through said open cell foam material when said plug is positioned in the canal.
 2. The ear plug of claim 1, wherein the wall of said hollow flared portion extends outwardly from said body portion, whereby the diameter of said flared portion is at least equal to the diameter of said body portion.
 3. An ear plug as defined in claim 1 in which said skin covers all of said structure except for two small areas on opposite ends of said plug to provide for pressure equalization when said plug is in use.
 4. An ear plug as defined in claim 1 in which said conical end has a maximum diameter less than that of said cylindrical body, said end and said body being joined by an angularly positioned shoulder.
 5. An ear plug as Defined in claim 4 in which said skin covers all of said structure except for two small areas on opposite ends of said plug to provide for pressure equalization when said plug is in use.
 6. An ear plug as defined in claim 4 in which said conical end is of a size to fit within the ear canal and said shoulder is of a size to bear against the portion of the ear surronding said canal. 